If you are users of earlier versions of Zorin then you will have seen a menu list of options at boot time. You may have been like me wondering if there was a bug in 12/12.1 - and it is something from research that Ubuntu users never got told or present in the wiki! When Zorin 12/12.1 boots you will see a blank screen with a pale blue/green border - this is the frame for GRUB and to see it you need to press the Right Shift Key!

[UPDATED 18.5.2013: If you have Windows on another Drive or GNU/Linux on another drive, when a kernel gets updated it will pick up the other OS's when updating GRUB, which will then show up without any need to press the correct Shift Key. ]